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Dumontier D, Liebman SA, Le VH, George S, Valdemar D, Van Aelst L, Pouchelon G. Restoring transient connectivity during development improves dysfunctions in fragile X mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.08.611918. [PMID: 39314327 PMCID: PMC11419037 DOI: 10.1101/2024.09.08.611918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Early-generated circuits are critical for the maturation of cortical network activity and the formation of excitation/inhibition (E/I) balance. This process involves the maturation of specific populations of inhibitory neurons. While parvalbumin (PV)-expressing neurons have been associated with E/I impairments observed in neurodevelopmental disorders, somatostatin-expressing (SST) neurons have recently been shown to regulate PV neuron maturation by controlling neural dynamics in the developing cortex. SST neurons receive transient connections from the sensory thalamus, yet the implications of transient connectivity in neurodevelopmental disorders remain unknown. Here, we show that thalamocortical connectivity to SST neurons is persistent rather than transient in a mouse model of Fragile X syndrome. We were able to restore the transient dynamics using chemogenetics, which led to the recovery of fragile X-associated dysfunctions in circuit maturation and sensory-dependent behavior. Overall, our findings unveil the role of early transient dynamics in controlling downstream maturation of sensory functions.
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Affiliation(s)
| | | | - Viet-Hang Le
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Shanu George
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
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2
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Falcão M, Monteiro P, Jacinto L. Tactile sensory processing deficits in genetic mouse models of autism spectrum disorder. J Neurochem 2024; 168:2105-2123. [PMID: 38837765 DOI: 10.1111/jnc.16135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/04/2024] [Accepted: 05/07/2024] [Indexed: 06/07/2024]
Abstract
Altered sensory processing is a common feature in autism spectrum disorder (ASD), as recognized in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Although altered responses to tactile stimuli are observed in over 60% of individuals with ASD, the neurobiological basis of this phenomenon is poorly understood. ASD has a strong genetic component and genetic mouse models can provide valuable insights into the mechanisms underlying tactile abnormalities in ASD. This review critically addresses recent findings regarding tactile processing deficits found in mouse models of ASD, with a focus on behavioral, anatomical, and functional alterations. Particular attention was given to cellular and circuit-level functional alterations, both in the peripheral and central nervous systems, with the objective of highlighting possible convergence mechanisms across models. By elucidating the impact of mutations in ASD candidate genes on somatosensory circuits and correlating them with behavioral phenotypes, this review significantly advances our understanding of tactile deficits in ASD. Such insights not only broaden our comprehension but also pave the way for future therapeutic interventions.
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Affiliation(s)
- Margarida Falcão
- Department of Biomedicine-Experimental Biology Unit, Faculty of Medicine of the University of Porto (FMUP), Porto, Portugal
| | - Patricia Monteiro
- Department of Biomedicine-Experimental Biology Unit, Faculty of Medicine of the University of Porto (FMUP), Porto, Portugal
| | - Luis Jacinto
- Department of Biomedicine-Experimental Biology Unit, Faculty of Medicine of the University of Porto (FMUP), Porto, Portugal
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3
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Wang HC, Feldman DE. Degraded tactile coding in the Cntnap2 mouse model of autism. Cell Rep 2024; 43:114612. [PMID: 39110592 PMCID: PMC11396660 DOI: 10.1016/j.celrep.2024.114612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 06/20/2024] [Accepted: 07/24/2024] [Indexed: 09/01/2024] Open
Abstract
Atypical sensory processing is common in autism, but how neural coding is disrupted in sensory cortex is unclear. We evaluate whisker touch coding in L2/3 of somatosensory cortex (S1) in Cntnap2-/- mice, which have reduced inhibition. This classically predicts excess pyramidal cell spiking, but this remains controversial, and other deficits may dominate. We find that c-fos expression is elevated in S1 of Cntnap2-/- mice under spontaneous activity conditions but is comparable to that of control mice after whisker stimulation, suggesting normal sensory-evoked spike rates. GCaMP8m imaging from L2/3 pyramidal cells shows no excess whisker responsiveness, but it does show multiple signs of degraded somatotopic coding. This includes broadened whisker-tuning curves, a blurred whisker map, and blunted whisker point representations. These disruptions are greater in noisy than in sparse sensory conditions. Tuning instability across days is also substantially elevated in Cntnap2-/-. Thus, Cntnap2-/- mice show no excess sensory-evoked activity, but a degraded and unstable tactile code in S1.
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Affiliation(s)
- Han Chin Wang
- Department of Molecular & Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Daniel E Feldman
- Department of Molecular & Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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4
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Moppert S, Mercado E. Contributions of dysfunctional plasticity mechanisms to the development of atypical perceptual processing. Dev Psychobiol 2024; 66:e22504. [PMID: 38837411 DOI: 10.1002/dev.22504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 03/04/2024] [Accepted: 05/11/2024] [Indexed: 06/07/2024]
Abstract
Experimental studies of sensory plasticity during development in birds and mammals have highlighted the importance of sensory experiences for the construction and refinement of functional neural circuits. We discuss how dysregulation of experience-dependent brain plasticity can lead to abnormal perceptual representations that may contribute to heterogeneous deficits symptomatic of several neurodevelopmental disorders. We focus on alterations of somatosensory processing and the dynamic reorganization of cortical synaptic networks that occurs during early perceptual development. We also discuss the idea that the heterogeneity of strengths and weaknesses observed in children with neurodevelopmental disorders may be a direct consequence of altered plasticity mechanisms during early development. Treating the heterogeneity of perceptual developmental trajectories as a phenomenon worthy of study rather than as an experimental confound that should be overcome may be key to developing interventions that better account for the complex developmental trajectories experienced by modern humans.
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Affiliation(s)
- Stacy Moppert
- Department of Psychology, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Eduardo Mercado
- Department of Psychology, University at Buffalo, The State University of New York, Buffalo, New York, USA
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5
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Wadle SL, Ritter TC, Wadle TTX, Hirtz JJ. Topography and Ensemble Activity in the Auditory Cortex of a Mouse Model of Fragile X Syndrome. eNeuro 2024; 11:ENEURO.0396-23.2024. [PMID: 38627066 PMCID: PMC11097631 DOI: 10.1523/eneuro.0396-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 03/11/2024] [Accepted: 04/01/2024] [Indexed: 05/18/2024] Open
Abstract
Autism spectrum disorder (ASD) is often associated with social communication impairments and specific sound processing deficits, for example, problems in following speech in noisy environments. To investigate underlying neuronal processing defects located in the auditory cortex (AC), we performed two-photon Ca2+ imaging in FMR1 (fragile X messenger ribonucleoprotein 1) knock-out (KO) mice, a model for fragile X syndrome (FXS), the most common cause of hereditary ASD in humans. For primary AC (A1) and the anterior auditory field (AAF), topographic frequency representation was less ordered compared with control animals. We additionally analyzed ensemble AC activity in response to various sounds and found subfield-specific differences. In A1, ensemble correlations were lower in general, while in secondary AC (A2), correlations were higher in response to complex sounds, but not to pure tones. Furthermore, sound specificity of ensemble activity was decreased in AAF. Repeating these experiments 1 week later revealed no major differences regarding representational drift. Nevertheless, we found subfield- and genotype-specific changes in ensemble correlation values between the two times points, hinting at alterations in network stability in FMR1 KO mice. These detailed insights into AC network activity and topography in FMR1 KO mice add to the understanding of auditory processing defects in FXS.
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Affiliation(s)
- Simon L Wadle
- Physiology of Neuronal Networks, Department of Biology, RPTU University of Kaiserslautern-Landau, Kaiserslautern D-67663, Germany
| | - Tamara C Ritter
- Physiology of Neuronal Networks, Department of Biology, RPTU University of Kaiserslautern-Landau, Kaiserslautern D-67663, Germany
| | - Tatjana T X Wadle
- Physiology of Neuronal Networks, Department of Biology, RPTU University of Kaiserslautern-Landau, Kaiserslautern D-67663, Germany
| | - Jan J Hirtz
- Physiology of Neuronal Networks, Department of Biology, RPTU University of Kaiserslautern-Landau, Kaiserslautern D-67663, Germany
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6
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Wu X, Liu Y, Wang X, Zheng L, Pan L, Wang H. Developmental Impairments of Synaptic Refinement in the Thalamus of a Mouse Model of Fragile X Syndrome. Neurosci Bull 2024; 40:439-450. [PMID: 38015349 PMCID: PMC11004103 DOI: 10.1007/s12264-023-01142-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 07/16/2023] [Indexed: 11/29/2023] Open
Abstract
While somatosensory over-reactivity is a common feature of autism spectrum disorders such as fragile X syndrome (FXS), the thalamic mechanisms underlying this remain unclear. Here, we found that the developmental elimination of synapses formed between the principal nucleus of V (PrV) and the ventral posterior medial nucleus (VPm) of the somatosensory system was delayed in fragile X mental retardation 1 gene knockout (Fmr1 KO) mice, while the developmental strengthening of these synapses was disrupted. Immunohistochemistry showed excessive VGluT2 puncta in mutants at P12-13, but not at P7-8 or P15-16, confirming a delay in somatic pruning of PrV-VPm synapses. Impaired synaptic function was associated with a reduction in the frequency of quantal AMPA events, as well as developmental deficits in presynaptic vesicle size and density. Our results uncovered the developmental impairment of thalamic relay synapses in Fmr1 KO mice and suggest that a thalamic contribution to the somatosensory over-reactivity in FXS should be considered.
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Affiliation(s)
- Xiaotong Wu
- Department of Neurosurgery of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang University School of Medicine, Hangzhou, 310058, China
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain Machine Integration, Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yali Liu
- Department of Neurosurgery of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain Machine Integration, Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Xiaomeng Wang
- Department of Neurosurgery of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang University School of Medicine, Hangzhou, 310058, China
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain Machine Integration, Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Lu Zheng
- Department of Neurosurgery of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain Machine Integration, Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Libiao Pan
- Department of Neurosurgery of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain Machine Integration, Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Hao Wang
- Department of Neurosurgery of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang University School of Medicine, Hangzhou, 310058, China.
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain Machine Integration, Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China.
- Lingang Laboratory, Shanghai, 200031, China.
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Bhaskaran AA, Gauvrit T, Vyas Y, Bony G, Ginger M, Frick A. Endogenous noise of neocortical neurons correlates with atypical sensory response variability in the Fmr1 -/y mouse model of autism. Nat Commun 2023; 14:7905. [PMID: 38036566 PMCID: PMC10689491 DOI: 10.1038/s41467-023-43777-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023] Open
Abstract
Excessive neural variability of sensory responses is a hallmark of atypical sensory processing in autistic individuals with cascading effects on other core autism symptoms but unknown neurobiological substrate. Here, by recording neocortical single neuron activity in a well-established mouse model of Fragile X syndrome and autism, we characterized atypical sensory processing and probed the role of endogenous noise sources in exaggerated response variability in males. The analysis of sensory stimulus evoked activity and spontaneous dynamics, as well as neuronal features, reveals a complex cellular and network phenotype. Neocortical sensory information processing is more variable and temporally imprecise. Increased trial-by-trial and inter-neuronal response variability is strongly related to key endogenous noise features, and may give rise to behavioural sensory responsiveness variability in autism. We provide a novel preclinical framework for understanding the sources of endogenous noise and its contribution to core autism symptoms, and for testing the functional consequences for mechanism-based manipulation of noise.
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Affiliation(s)
- Arjun A Bhaskaran
- INSERM, U1215 Neurocentre Magendie, 33077, Bordeaux, France
- University of Bordeaux, 33000, Bordeaux, France
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Théo Gauvrit
- INSERM, U1215 Neurocentre Magendie, 33077, Bordeaux, France
- University of Bordeaux, 33000, Bordeaux, France
| | - Yukti Vyas
- INSERM, U1215 Neurocentre Magendie, 33077, Bordeaux, France
- University of Bordeaux, 33000, Bordeaux, France
| | - Guillaume Bony
- INSERM, U1215 Neurocentre Magendie, 33077, Bordeaux, France
- University of Bordeaux, 33000, Bordeaux, France
| | - Melanie Ginger
- INSERM, U1215 Neurocentre Magendie, 33077, Bordeaux, France
- University of Bordeaux, 33000, Bordeaux, France
| | - Andreas Frick
- INSERM, U1215 Neurocentre Magendie, 33077, Bordeaux, France.
- University of Bordeaux, 33000, Bordeaux, France.
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8
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Wang HC, Feldman DE. Degraded tactile coding in the Cntnap2 mouse model of autism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.29.560240. [PMID: 37808857 PMCID: PMC10557772 DOI: 10.1101/2023.09.29.560240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Atypical sensory processing in autism involves altered neural circuit function and neural coding in sensory cortex, but the nature of coding disruption is poorly understood. We characterized neural coding in L2/3 of whisker somatosensory cortex (S1) of Cntnap2-/- mice, an autism model with pronounced hypofunction of parvalbumin (PV) inhibitory circuits. We tested for both excess spiking, which is often hypothesized in autism models with reduced inhibition, and alterations in somatotopic coding, using c-fos immunostaining and 2-photon calcium imaging in awake mice. In Cntnap2-/- mice, c-fos-(+) neuron density was elevated in L2/3 of S1 under spontaneous activity conditions, but comparable to control mice after whisker stimulation, suggesting that sensory-evoked spiking was relatively normal. 2-photon GCaMP8m imaging in L2/3 pyramidal cells revealed no increase in whisker-evoked response magnitude, but instead showed multiple signs of degraded somatotopic coding. These included broadening of whisker tuning curves, blurring of the whisker map, and blunting of the point representation of each whisker. These altered properties were more pronounced in noisy than sparse sensory conditions. Tuning instability, assessed over 2-3 weeks of longitudinal imaging, was also significantly increased in Cntnap2-/- mice. Thus, Cntnap2-/- mice show no excess spiking, but a degraded and unstable tactile code in S1.
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Affiliation(s)
- Han Chin Wang
- Department of Molecular & Cell Biology, and Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California 94720, USA
| | - Daniel E. Feldman
- Department of Molecular & Cell Biology, and Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California 94720, USA
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9
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Monday HR, Wang HC, Feldman DE. Circuit-level theories for sensory dysfunction in autism: convergence across mouse models. Front Neurol 2023; 14:1254297. [PMID: 37745660 PMCID: PMC10513044 DOI: 10.3389/fneur.2023.1254297] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 08/14/2023] [Indexed: 09/26/2023] Open
Abstract
Individuals with autism spectrum disorder (ASD) exhibit a diverse range of behavioral features and genetic backgrounds, but whether different genetic forms of autism involve convergent pathophysiology of brain function is unknown. Here, we analyze evidence for convergent deficits in neural circuit function across multiple transgenic mouse models of ASD. We focus on sensory areas of neocortex, where circuit differences may underlie atypical sensory processing, a central feature of autism. Many distinct circuit-level theories for ASD have been proposed, including increased excitation-inhibition (E-I) ratio and hyperexcitability, hypofunction of parvalbumin (PV) interneuron circuits, impaired homeostatic plasticity, degraded sensory coding, and others. We review these theories and assess the degree of convergence across ASD mouse models for each. Behaviorally, our analysis reveals that innate sensory detection behavior is heightened and sensory discrimination behavior is impaired across many ASD models. Neurophysiologically, PV hypofunction and increased E-I ratio are prevalent but only rarely generate hyperexcitability and excess spiking. Instead, sensory tuning and other aspects of neural coding are commonly degraded and may explain impaired discrimination behavior. Two distinct phenotypic clusters with opposing neural circuit signatures are evident across mouse models. Such clustering could suggest physiological subtypes of autism, which may facilitate the development of tailored therapeutic approaches.
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Affiliation(s)
- Hannah R. Monday
- Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
| | | | - Daniel E. Feldman
- Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
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Kuruppath P, Xue L, Pouille F, Jones ST, Schoppa NE. Hyperexcitability in the olfactory bulb and impaired fine odor discrimination in the Fmr1 KO mouse model of fragile X syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.10.536251. [PMID: 37090519 PMCID: PMC10120685 DOI: 10.1101/2023.04.10.536251] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Fragile X syndrome (FXS) is the single most common monogenetic cause of autism spectrum disorders in humans. FXS is caused by loss of expression of the Fragile X mental retardation protein (FMRP), an mRNA-binding protein encoded on the X chromosome involved in suppressing protein translation. Sensory processing deficits have been a major focus of studies of FXS in both humans and rodent models of FXS, but olfactory deficits remain poorly understood. Here we conducted experiments in wild-type and Fmr1 KO ( Fmr1 -/y ) mice (males) that lack expression of the gene encoding FMRP to assess olfactory circuit and behavioral abnormalities. In patch-clamp recordings conducted in slices of the olfactory bulb, output mitral cells (MCs) in Fmr1 KO mice displayed greatly enhanced excitation, as evidenced by a much higher rate of occurrence of spontaneous network-level events known as long-lasting depolarizations (LLDs). The higher probability of LLDs did not appear to reflect changes in inhibitory connections onto MCs but rather enhanced spontaneous excitation of external tufted cells (eTCs) that provide feedforward excitation onto MCs within glomeruli. In addition, in a go/no-go operant discrimination paradigm, we found that Fmr1 KO mice displayed impaired discrimination of odors in difficult tasks that involved odor mixtures but not altered discrimination of monomolecular odors. We suggest that the higher excitability of MCs in Fmr1 KO mice may impair fine odor discrimination by broadening odor tuning curves of MCs and/or altering synchronized oscillations through changes in transient inhibition. Significance Statement Fragile X syndrome (FXS) in humans is associated with a range of debilitating deficits including aberrant sensory processing. One sensory system that has received comparatively little attention in studies in animal models of FXS is olfaction. Here, we report the first comprehensive physiological analysis of circuit defects in the olfactory bulb in the commonly-used Fmr1 knockout (KO) mouse model of FXS. Our studies indicate that Fmr1 KO alters the local excitation/inhibition balance in the bulb - similar to what Fmr1 KO does in other brain circuits - but through a novel mechanism that involves enhanced feedforward excitatory drive. Furthermore, Fmr1 KO mice display behavioral impairments in fine odor discrimination, an effect that may be explained by enhanced neural excitability.
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Diamond ME, Toso A. Tactile cognition in rodents. Neurosci Biobehav Rev 2023; 149:105161. [PMID: 37028580 DOI: 10.1016/j.neubiorev.2023.105161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/23/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023]
Abstract
Since the discovery 50 years ago of the precisely ordered representation of the whiskers in somatosensory cortex, the rodent tactile sensory system has been a fertile ground for the study of sensory processing. With the growing sophistication of touch-based behavioral paradigms, together with advances in neurophysiological methodology, a new approach is emerging. By posing increasingly complex perceptual and memory problems, in many cases analogous to human psychophysical tasks, investigators now explore the operations underlying rodent problem solving. We define the neural basis of tactile cognition as the transformation from a stage in which neuronal activity encodes elemental features, local in space and in time, to a stage in which neuronal activity is an explicit representation of the behavioral operations underlying the current task. Selecting a set of whisker-based behavioral tasks, we show that rodents achieve high level performance through the workings of neuronal circuits that are accessible, decodable, and manipulatable. As a means towards exploring tactile cognition, this review presents leading psychophysical paradigms and, where known, their neural correlates.
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Affiliation(s)
- Mathew E Diamond
- Cognitive Neuroscience, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste, Italy.
| | - Alessandro Toso
- Cognitive Neuroscience, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste, Italy
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12
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Gredell M, Lu J, Zuo Y. The effect of single-cell knockout of Fragile X Messenger Ribonucleoprotein on synaptic structural plasticity. Front Synaptic Neurosci 2023; 15:1135479. [PMID: 37035256 PMCID: PMC10076639 DOI: 10.3389/fnsyn.2023.1135479] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 03/07/2023] [Indexed: 04/11/2023] Open
Abstract
Fragile X Syndrome (FXS) is the best-known form of inherited intellectual disability caused by the loss-of-function mutation in a single gene. The FMR1 gene mutation abolishes the expression of Fragile X Messenger Ribonucleoprotein (FMRP), which regulates the expression of many synaptic proteins. Cortical pyramidal neurons in postmortem FXS patient brains show abnormally high density and immature morphology of dendritic spines; this phenotype is replicated in the Fmr1 knockout (KO) mouse. While FMRP is well-positioned in the dendrite to regulate synaptic plasticity, intriguing in vitro and in vivo data show that wild type neurons embedded in a network of Fmr1 KO neurons or glia exhibit spine abnormalities just as neurons in Fmr1 global KO mice. This raises the question: does FMRP regulate synaptic morphology and dynamics in a cell-autonomous manner, or do the synaptic phenotypes arise from abnormal pre-synaptic inputs? To address this question, we combined viral and mouse genetic approaches to delete FMRP from a very sparse subset of cortical layer 5 pyramidal neurons (L5 PyrNs) either during early postnatal development or in adulthood. We then followed the structural dynamics of dendritic spines on these Fmr1 KO neurons by in vivo two-photon microscopy. We found that, while L5 PyrNs in adult Fmr1 global KO mice have abnormally high density of thin spines, single-cell Fmr1 KO in adulthood does not affect spine density, morphology, or dynamics. On the contrary, neurons with neonatal FMRP deletion have normal spine density but elevated spine formation at 1 month of age, replicating the phenotype in Fmr1 global KO mice. Interestingly, these neurons exhibit elevated thin spine density, but normal total spine density, by adulthood. Together, our data reveal cell-autonomous FMRP regulation of cortical synaptic dynamics during adolescence, but spine defects in adulthood also implicate non-cell-autonomous factors.
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Affiliation(s)
| | | | - Yi Zuo
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
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13
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Wu C, Shang HF, Wang YJ, Wang JH, Zuo ZX, Lian YN, Liu L, Zhang C, Li XY. Cingulate protein arginine methyltransferases 1 regulates peripheral hypersensitivity via fragile X messenger ribonucleoprotein. Front Mol Neurosci 2023; 16:1153870. [PMID: 37152432 PMCID: PMC10158607 DOI: 10.3389/fnmol.2023.1153870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/24/2023] [Indexed: 05/09/2023] Open
Abstract
The deficit of fragile X messenger ribonucleoprotein (FMRP) leads to intellectual disability in human and animal models, which also leads to desensitization of pain after nerve injury. Recently, it was shown that the protein arginine methyltransferases 1 (PRMT1) regulates the phase separation of FMRP. However, the role of PRMT1 in pain regulation has been less investigated. Here we showed that the downregulation of PRMT1 in the anterior cingulate cortex (ACC) contributes to the development of peripheral pain hypersensitivity. We observed that the peripheral nerve injury decreased the expression of PRMT1 in the ACC; knockdown of the PRMT1 via shRNA in the ACC decreased the paw withdrawal thresholds (PWTs) of naïve mice. Moreover, the deficits of FMRP abolished the effects of PRMT1 on pain sensation. Furthermore, overexpression of PRMT1 in the ACC increased the PWTs of mice with nerve injury. These observations indicate that the downregulation of cingulate PRMT1 was necessary and sufficient to develop peripheral hypersensitivity after nerve injury. Thus, we provided evidence that PRMT1 is vital in regulating peripheral pain hypersensitivity after nerve injury via the FMRP.
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Affiliation(s)
- Cheng Wu
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
- Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- International Institutes of Medicine, The Forth Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Yiwu, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Hui-Fang Shang
- International Institutes of Medicine, The Forth Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Yiwu, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Yong-Jie Wang
- International Institutes of Medicine, The Forth Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Yiwu, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Jing-Hua Wang
- International Institutes of Medicine, The Forth Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Yiwu, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Zhen-Xing Zuo
- Department of Neurosurgery, Tenth People’s Hospital, Shanghai, China
| | - Yan-Na Lian
- International Institutes of Medicine, The Forth Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Yiwu, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Li Liu
- Core Facilities of the School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chen Zhang
- School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Xiang-Yao Li
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
- Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- International Institutes of Medicine, The Forth Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Yiwu, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
- *Correspondence: Xiang-Yao Li,
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14
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Deng PY, Avraham O, Cavalli V, Klyachko VA. Hyperexcitability of Sensory Neurons in Fragile X Mouse Model. Front Mol Neurosci 2022; 14:796053. [PMID: 35002623 PMCID: PMC8727524 DOI: 10.3389/fnmol.2021.796053] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/17/2021] [Indexed: 01/18/2023] Open
Abstract
Sensory hypersensitivity and somatosensory deficits represent the core symptoms of Fragile X syndrome (FXS). These alterations are believed to arise from changes in cortical sensory processing, while potential deficits in the function of peripheral sensory neurons residing in dorsal root ganglia remain unexplored. We found that peripheral sensory neurons exhibit pronounced hyperexcitability in Fmr1 KO mice, manifested by markedly increased action potential (AP) firing rate and decreased threshold. Unlike excitability changes found in many central neurons, no significant changes were observed in AP rising and falling time, peak potential, amplitude, or duration. Sensory neuron hyperexcitability was caused primarily by increased input resistance, without changes in cell capacitance or resting membrane potential. Analyses of the underlying mechanisms revealed reduced activity of HCN channels and reduced expression of HCN1 and HCN4 in Fmr1 KO compared to WT. A selective HCN channel blocker abolished differences in all measures of sensory neuron excitability between WT and Fmr1 KO neurons. These results reveal a hyperexcitable state of peripheral sensory neurons in Fmr1 KO mice caused by dysfunction of HCN channels. In addition to the intrinsic neuronal dysfunction, the accompanying paper examines deficits in sensory neuron association/communication with their enveloping satellite glial cells, suggesting contributions from both neuronal intrinsic and extrinsic mechanisms to sensory dysfunction in the FXS mouse model.
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Affiliation(s)
- Pan-Yue Deng
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Oshri Avraham
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Valeria Cavalli
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States.,Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States.,Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Vitaly A Klyachko
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States.,Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States
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15
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Negwer M, Piera K, Hesen R, Lütje L, Aarts L, Schubert D, Nadif Kasri N. EHMT1 regulates Parvalbumin-positive interneuron development and GABAergic input in sensory cortical areas. Brain Struct Funct 2020; 225:2701-2716. [PMID: 32975655 PMCID: PMC7674571 DOI: 10.1007/s00429-020-02149-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 09/10/2020] [Indexed: 02/08/2023]
Abstract
Mutations in the Euchromatic Histone Methyltransferase 1 (EHMT1) gene cause Kleefstra syndrome, a rare form of intellectual disability (ID) with strong autistic traits and sensory processing deficits. Proper development of inhibitory interneurons is crucial for sensory function. Here we report a timeline of Parvalbumin-positive (PV+) interneuron development in the three most important sensory cortical areas in the Ehmt1+/- mouse. We find a hitherto unreported delay of PV+ neuron maturation early in sensory development, with layer- and region-specific variability later in development. The delayed PV+ maturation is also reflected in a delayed maturation of GABAergic transmission in Ehmt1+/- auditory cortex, where we find a reduced GABA release probability specifically in putative PV+ synapses. Together with earlier reports of excitatory impairments in Ehmt1+/- neurons, we propose a shift in excitatory-inhibitory balance towards overexcitability in Ehmt1+/- sensory cortices as a consequence of early deficits in inhibitory maturation.
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Affiliation(s)
- Moritz Negwer
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Karol Piera
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Rick Hesen
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Lukas Lütje
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Lynn Aarts
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB, Nijmegen, The Netherlands.
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, 6500 HB, Nijmegen, The Netherlands.
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16
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Ansorge J, Humanes‐Valera D, Pauzin FP, Schwarz MK, Krieger P. Cortical layer 6 control of sensory responses in higher‐order thalamus. J Physiol 2020; 598:3973-4001. [DOI: 10.1113/jp279915] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 06/22/2020] [Indexed: 12/29/2022] Open
Affiliation(s)
- Josephine Ansorge
- Faculty of Medicine, Department of Systems Neuroscience Ruhr University Bochum Bochum Germany
| | - Desire Humanes‐Valera
- Faculty of Medicine, Department of Systems Neuroscience Ruhr University Bochum Bochum Germany
| | - François P. Pauzin
- Faculty of Medicine, Department of Systems Neuroscience Ruhr University Bochum Bochum Germany
| | - Martin K. Schwarz
- Institute of Experimental Epileptology and Cognition Research University of Bonn Medical School Bonn Germany
| | - Patrik Krieger
- Faculty of Medicine, Department of Systems Neuroscience Ruhr University Bochum Bochum Germany
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17
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Möhrle D, Fernández M, Peñagarikano O, Frick A, Allman B, Schmid S. What we can learn from a genetic rodent model about autism. Neurosci Biobehav Rev 2020; 109:29-53. [DOI: 10.1016/j.neubiorev.2019.12.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/28/2019] [Accepted: 12/10/2019] [Indexed: 12/15/2022]
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18
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Pauzin FP, Schwarz N, Krieger P. Activation of Corticothalamic Layer 6 Cells Decreases Angular Tuning in Mouse Barrel Cortex. Front Neural Circuits 2019; 13:67. [PMID: 31736714 PMCID: PMC6838007 DOI: 10.3389/fncir.2019.00067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/30/2019] [Indexed: 01/21/2023] Open
Abstract
In the mouse whisker system, the contribution of L6 corticothalamic cells (L6 CT) to cortical and thalamic processing of the whisker deflection direction was investigated. A genetically defined population of L6 CT cells project to infragranular GABAergic interneurons that hyperpolarize neurons in somatosensory barrel cortex (BC). Optogenetic activation of these neurons switched BC to an adapted mode in which excitatory cells lost their angular tuning. In contrast, however, this was not the case with a general activation of inhibitory interneurons via optogenetic activation of Gad2-expressing cells. The decrease in angular tuning, when L6 CT cells were activated, was due to changes in cortical inhibition, and not inherited from changes in the thalamic output. Furthermore, L6 CT driven cortical inhibition, but not the general activation of GABAergic interneurons, abolished adaptation to whisker responses. In the present study, evidence is presented that a subpopulation of L6 CT activates a specific circuit of GABAergic interneurons that will predispose neocortex toward processing of tactile information requiring multiple whisker touches, such as in a texture discrimination task.
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Affiliation(s)
- François Philippe Pauzin
- Department of Systems Neuroscience, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Nadja Schwarz
- Department of Systems Neuroscience, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Patrik Krieger
- Department of Systems Neuroscience, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
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19
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Abstract
OBJECTIVE Close-loop control of brain and behavior will benefit from real-time detection of behavioral events to enable low-latency communication with peripheral devices. In animal experiments, this is typically achieved by using sparsely distributed (embedded) sensors that detect animal presence in select regions of interest. High-speed cameras provide high-density sampling across large arenas, capturing the richness of animal behavior, however, the image processing bottleneck prohibits real-time feedback in the context of rapidly evolving behaviors. APPROACH Here we developed an open-source software, named PolyTouch, to track animal behavior in large arenas and provide rapid close-loop feedback in ~5.7 ms, ie. average latency from the detection of an event to analog stimulus delivery, e.g. auditory tone, TTL pulse, when tracking a single body. This stand-alone software is written in JAVA. The included wrapper for MATLAB provides experimental flexibility for data acquisition, analysis and visualization. MAIN RESULTS As a proof-of-principle application we deployed the PolyTouch for place awareness training. A user-defined portion of the arena was used as a virtual target; visit (or approach) to the target triggered auditory feedback. We show that mice develop awareness to virtual spaces, tend to stay shorter and move faster when they reside in the virtual target zone if their visits are coupled to relatively high stimulus intensity (⩾49 dB). Thus, close-loop presentation of perceived aversive feedback is sufficient to condition mice to avoid virtual targets within the span of a single session (~20 min). SIGNIFICANCE Neuromodulation techniques now allow control of neural activity in a cell-type specific manner in spiking resolution. Using animal behavior to drive closed-loop control of neural activity would help to address the neural basis of behavioral state and environmental context-dependent information processing in the brain.
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20
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Multifaceted Changes in Synaptic Composition and Astrocytic Involvement in a Mouse Model of Fragile X Syndrome. Sci Rep 2019; 9:13855. [PMID: 31554841 PMCID: PMC6761194 DOI: 10.1038/s41598-019-50240-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/09/2019] [Indexed: 12/20/2022] Open
Abstract
Fragile X Syndrome (FXS), a common inheritable form of intellectual disability, is known to alter neocortical circuits. However, its impact on the diverse synapse types comprising these circuits, or on the involvement of astrocytes, is not well known. We used immunofluorescent array tomography to quantify different synaptic populations and their association with astrocytes in layers 1 through 4 of the adult somatosensory cortex of a FXS mouse model, the FMR1 knockout mouse. The collected multi-channel data contained approximately 1.6 million synapses which were analyzed using a probabilistic synapse detector. Our study reveals complex, synapse-type and layer specific changes in the neocortical circuitry of FMR1 knockout mice. We report an increase of small glutamatergic VGluT1 synapses in layer 4 accompanied by a decrease in large VGluT1 synapses in layers 1 and 4. VGluT2 synapses show a rather consistent decrease in density in layers 1 and 2/3. In all layers, we observe the loss of large inhibitory synapses. Lastly, astrocytic association of excitatory synapses decreases. The ability to dissect the circuit deficits by synapse type and astrocytic involvement will be crucial for understanding how these changes affect circuit function, and ultimately defining targets for therapeutic intervention.
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21
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Abstract
In this issue of Neuron, Antoine et al. (2019) find reduced feedforward inhibition in cortical neurons in four genetic mouse models of autism but without evidence of increased spontaneous or sensory-evoked activity.
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22
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Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder that causes intellectual disability. It is a leading known genetic cause of autism. In addition to cognitive, social, and communication deficits, humans with FXS demonstrate abnormal sensory processing including sensory hypersensitivity. Sensory hypersensitivity commonly manifests as auditory, tactile, or visual defensiveness or avoidance. Clinical, behavioral, and electrophysiological studies consistently show auditory hypersensitivity, impaired habituation to repeated sounds, and reduced auditory attention in humans with FXS. Children with FXS also exhibit significant visuospatial impairments. Studies in infants and toddlers with FXS have documented impairments in processing texture-defined motion stimuli, temporal flicker, perceiving ordinal numerical sequence, and the ability to maintain the identity of dynamic object information during occlusion. Consistent with the observations in humans with FXS, fragile X mental retardation 1 ( Fmr1) gene knockout (KO) rodent models of FXS also show seizures, abnormal visual-evoked responses, auditory hypersensitivity, and abnormal processing at multiple levels of the auditory system, including altered acoustic startle responses. Among other sensory symptoms, individuals with FXS exhibit tactile defensiveness. Fmr1 KO mice also show impaired encoding of tactile stimulation frequency and larger size of receptive fields in the somatosensory cortex. Since sensory deficits are relatively more tractable from circuit mechanisms and developmental perspectives than more complex social behaviors, the focus of this review is on clinical, functional, and structural studies that outline the auditory, visual, and somatosensory processing deficits in FXS. The similarities in sensory phenotypes between humans with FXS and animal models suggest a likely conservation of basic sensory processing circuits across species and may provide a translational platform to not just develop biomarkers but also to understand underlying mechanisms. We argue that preclinical studies in animal models of FXS can facilitate the ongoing search for new therapeutic approaches in FXS by understanding mechanisms of basic sensory processing circuits and behaviors that are conserved across species.
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Affiliation(s)
- Maham Rais
- 1 Division of Biomedical Sciences, University of California Riverside School of Medicine, CA, USA.,2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA
| | - Devin K Binder
- 1 Division of Biomedical Sciences, University of California Riverside School of Medicine, CA, USA.,2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA.,3 Neuroscience Graduate Program, University of California Riverside, CA, USA
| | - Khaleel A Razak
- 2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA.,3 Neuroscience Graduate Program, University of California Riverside, CA, USA.,4 Psychology Department, University of California Riverside, CA, USA
| | - Iryna M Ethell
- 1 Division of Biomedical Sciences, University of California Riverside School of Medicine, CA, USA.,2 Biomedical Sciences Graduate Program, University of California Riverside, CA, USA.,3 Neuroscience Graduate Program, University of California Riverside, CA, USA
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23
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Bodaleo F, Tapia-Monsalves C, Cea-Del Rio C, Gonzalez-Billault C, Nunez-Parra A. Structural and Functional Abnormalities in the Olfactory System of Fragile X Syndrome Models. Front Mol Neurosci 2019; 12:135. [PMID: 31191246 PMCID: PMC6548058 DOI: 10.3389/fnmol.2019.00135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/09/2019] [Indexed: 12/18/2022] Open
Abstract
Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability. It is produced by mutation of the Fmr1 gene that encodes for the Fragile Mental Retardation Protein (FMRP), an important RNA-binding protein that regulates the expression of multiple proteins located in neuronal synapses. Individuals with FXS exhibit abnormal sensory information processing frequently leading to hypersensitivity across sensory modalities and consequently a wide array of behavioral symptoms. Insects and mammals engage primarily their sense of smell to create proper representations of the external world and guide adequate decision-making processes. This feature in combination with the exquisitely organized neuronal circuits found throughout the olfactory system (OS) and the wide expression of FMRP in brain regions that process olfactory information makes it an ideal model to study sensory alterations in FXS models. In the last decade several groups have taken advantage of these features and have used the OS of fruit fly and rodents to understand neuronal alteration giving rise to sensory perception issues. In this review article, we will discuss molecular, morphological and physiological aspects of the olfactory information processing in FXS models. We will highlight the decreased inhibitory/excitatory synaptic balance and the diminished synaptic plasticity found in this system resulting in behavioral alteration of individuals in the presence of odorant stimuli.
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Affiliation(s)
- Felipe Bodaleo
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | | | - Christian Cea-Del Rio
- Laboratory of Neurophysiopathology, Centro de Investigacion Biomedica y Aplicada (CIBAP), School of Medicine, Universidad de Santiago de Chile, Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, CA, United States
| | - Alexia Nunez-Parra
- Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Cell Physiology Center, Universidad de Chile, Santiago, Chile
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24
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Chelini G, Zerbi V, Cimino L, Grigoli A, Markicevic M, Libera F, Robbiati S, Gadler M, Bronzoni S, Miorelli S, Galbusera A, Gozzi A, Casarosa S, Provenzano G, Bozzi Y. Aberrant Somatosensory Processing and Connectivity in Mice Lacking Engrailed-2. J Neurosci 2019; 39:1525-1538. [PMID: 30593497 PMCID: PMC6381254 DOI: 10.1523/jneurosci.0612-18.2018] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 12/12/2018] [Accepted: 12/14/2018] [Indexed: 11/21/2022] Open
Abstract
Overreactivity and defensive behaviors in response to tactile stimuli are common symptoms in autism spectrum disorder (ASD) patients. Similarly, somatosensory hypersensitivity has also been described in mice lacking ASD-associated genes such as Fmr1 (fragile X mental retardation protein 1). Fmr1 knock-out mice also show reduced functional connectivity between sensory cortical areas, which may represent an endogenous biomarker for their hypersensitivity. Here, we measured whole-brain functional connectivity in Engrailed-2 knock-out (En2-/-) adult mice, which show a lower expression of Fmr1 and anatomical defects common to Fmr1 knock-outs. MRI-based resting-state functional connectivity in adult En2-/- mice revealed significantly reduced synchronization in somatosensory-auditory/associative cortices and dorsal thalamus, suggesting the presence of aberrant somatosensory processing in these mutants. Accordingly, when tested in the whisker nuisance test, En2-/- but not WT mice of both sexes showed fear behavior in response to repeated whisker stimulation. En2-/- mice undergoing this test exhibited decreased c-Fos-positive neurons (a marker of neuronal activity) in layer IV of the primary somatosensory cortex and increased immunoreactive cells in the basolateral amygdala compared with WT littermates. Conversely, when tested in a sensory maze, En2-/- and WT mice spent a comparable time in whisker-guided exploration, indicating that whisker-mediated behaviors are otherwise preserved in En2 mutants. Therefore, fearful responses to somatosensory stimuli in En2-/- mice are accompanied by reduced basal connectivity of sensory regions, reduced activation of somatosensory cortex, and increased activation of the basolateral amygdala, suggesting that impaired somatosensory processing is a common feature in mice lacking ASD-related genes.SIGNIFICANCE STATEMENT Overreactivity to tactile stimuli is a common symptom in autism spectrum disorder (ASD) patients. Recent studies performed in mice bearing ASD-related mutations confirmed these findings. Here, we evaluated the behavioral response to whisker stimulation in mice lacking the ASD-related gene Engrailed-2 (En2-/- mice). Compared with WT controls, En2-/- mice showed reduced functional connectivity in the somatosensory cortex, which was paralleled by fear behavior, reduced activation of somatosensory cortex, and increased activation of the basolateral amygdala in response to repeated whisker stimulation. These results suggest that impaired somatosensory signal processing is a common feature in mice harboring ASD-related mutations.
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Affiliation(s)
- Gabriele Chelini
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
| | - Valerio Zerbi
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule (ETH) Zürich, 8057 Zurich, Switzerland
| | - Luca Cimino
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
| | - Andrea Grigoli
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
| | - Marija Markicevic
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule (ETH) Zürich, 8057 Zurich, Switzerland
| | - Francesco Libera
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38068 Rovereto, Italy
| | - Sergio Robbiati
- Model Organisms Facility, Center for Integrative Biology, University of Trento, 38123 Trento, Italy
| | - Mattia Gadler
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
| | - Silvia Bronzoni
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38068 Rovereto, Italy
| | - Silvia Miorelli
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
| | - Alberto Galbusera
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy, and
| | - Alessandro Gozzi
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy, and
| | - Simona Casarosa
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
- CNR Neuroscience Institute, 56124 Pisa, Italy
| | - Giovanni Provenzano
- Center for Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy,
| | - Yuri Bozzi
- Center for Mind/Brain Sciences (CIMeC), University of Trento, 38068 Rovereto, Italy,
- CNR Neuroscience Institute, 56124 Pisa, Italy
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25
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Antoine MW, Langberg T, Schnepel P, Feldman DE. Increased Excitation-Inhibition Ratio Stabilizes Synapse and Circuit Excitability in Four Autism Mouse Models. Neuron 2019; 101:648-661.e4. [PMID: 30679017 DOI: 10.1016/j.neuron.2018.12.026] [Citation(s) in RCA: 241] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 11/19/2018] [Accepted: 12/19/2018] [Indexed: 01/08/2023]
Abstract
Distinct genetic forms of autism are hypothesized to share a common increase in excitation-inhibition (E-I) ratio in cerebral cortex, causing hyperexcitability and excess spiking. We provide a systematic test of this hypothesis across 4 mouse models (Fmr1-/y, Cntnap2-/-, 16p11.2del/+, Tsc2+/-), focusing on somatosensory cortex. All autism mutants showed reduced feedforward inhibition in layer 2/3 coupled with more modest, variable reduction in feedforward excitation, driving a common increase in E-I conductance ratio. Despite this, feedforward spiking, synaptic depolarization, and spontaneous spiking were largely normal. Modeling revealed that E and I conductance changes in each mutant were quantitatively matched to yield stable, not increased, synaptic depolarization for cells near spike threshold. Correspondingly, whisker-evoked spiking was not increased in vivo despite detectably reduced inhibition. Thus, elevated E-I ratio is a common circuit phenotype but appears to reflect homeostatic stabilization of synaptic drive rather than driving network hyperexcitability in autism.
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Affiliation(s)
- Michelle W Antoine
- Department of Molecular and Cellular Biology and Helen Wills Neuroscience Institute, UC Berkeley, Berkeley, CA 94720, USA.
| | - Tomer Langberg
- Department of Molecular and Cellular Biology and Helen Wills Neuroscience Institute, UC Berkeley, Berkeley, CA 94720, USA
| | - Philipp Schnepel
- Department of Molecular and Cellular Biology and Helen Wills Neuroscience Institute, UC Berkeley, Berkeley, CA 94720, USA
| | - Daniel E Feldman
- Department of Molecular and Cellular Biology and Helen Wills Neuroscience Institute, UC Berkeley, Berkeley, CA 94720, USA.
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26
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da Silva Lantyer A, Calcini N, Bijlsma A, Kole K, Emmelkamp M, Peeters M, Scheenen WJJ, Zeldenrust F, Celikel T. A databank for intracellular electrophysiological mapping of the adult somatosensory cortex. Gigascience 2018; 7:5232232. [PMID: 30521020 PMCID: PMC6302958 DOI: 10.1093/gigascience/giy147] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 11/18/2018] [Indexed: 02/04/2023] Open
Abstract
Background Neurons in the supragranular layers of the somatosensory cortex integrate sensory (bottom-up) and cognitive/perceptual (top-down) information as they orchestrate communication across cortical columns. It has been inferred, based on intracellular recordings from juvenile animals, that supragranular neurons are electrically mature by the fourth postnatal week. However, the dynamics of the neuronal integration in adulthood is largely unknown. Electrophysiological characterization of the active properties of these neurons throughout adulthood will help to address the biophysical and computational principles of the neuronal integration. Findings Here, we provide a database of whole-cell intracellular recordings from 315 neurons located in the supragranular layers (L2/3) of the primary somatosensory cortex in adult mice (9–45 weeks old) from both sexes (females, N = 195; males, N = 120). Data include 361 somatic current-clamp (CC) and 476 voltage-clamp (VC) experiments, recorded using a step-and-hold protocol (CC, N = 257; VC, N = 46), frozen noise injections (CC, N = 104) and triangular voltage sweeps (VC, 10 (N = 132), 50 (N = 146) and 100 ms (N = 152)), from regular spiking (N = 169) and fast-spiking neurons (N = 66). Conclusions The data can be used to systematically study the properties of somatic integration and the principles of action potential generation across sexes and across electrically characterized neuronal classes in adulthood. Understanding the principles of the somatic transformation of postsynaptic potentials into action potentials will shed light onto the computational principles of intracellular information transfer in single neurons and information processing in neuronal networks, helping to recreate neuronal functions in artificial systems.
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Affiliation(s)
- Angelica da Silva Lantyer
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Niccolò Calcini
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Ate Bijlsma
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Koen Kole
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Melanie Emmelkamp
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Manon Peeters
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Wim J J Scheenen
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Fleur Zeldenrust
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
| | - Tansu Celikel
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Heyedaalseweg 135, 6525 HJ, Nijmegen - the Netherlands
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27
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Azarfar A, Zhang Y, Alishbayli A, Miceli S, Kepser L, van der Wielen D, van de Moosdijk M, Homberg J, Schubert D, Proville R, Celikel T. An open-source high-speed infrared videography database to study the principles of active sensing in freely navigating rodents. Gigascience 2018; 7:5168870. [PMID: 30418576 PMCID: PMC6283211 DOI: 10.1093/gigascience/giy134] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 10/21/2018] [Indexed: 11/12/2022] Open
Abstract
Background Active sensing is crucial for navigation. It is characterized by self-generated motor action controlling the accessibility and processing of sensory information. In rodents, active sensing is commonly studied in the whisker system. As rats and mice modulate their whisking contextually, they employ frequency and amplitude modulation. Understanding the development, mechanisms, and plasticity of adaptive motor control will require precise behavioral measurements of whisker position. Findings Advances in high-speed videography and analytical methods now permit collection and systematic analysis of large datasets. Here, we provide 6,642 videos as freely moving juvenile (third to fourth postnatal week) and adult rodents explore a stationary object on the gap-crossing task. The dataset includes sensory exploration with single- or multi-whiskers in wild-type animals, serotonin transporter knockout rats, rats received pharmacological intervention targeting serotonergic signaling. The dataset includes varying background illumination conditions and signal-to-noise ratios (SNRs), ranging from homogenous/high contrast to non-homogenous/low contrast. A subset of videos has been whisker and nose tracked and are provided as reference for image processing algorithms. Conclusions The recorded behavioral data can be directly used to study development of sensorimotor computation, top-down mechanisms that control sensory navigation and whisker position, and cross-species comparison of active sensing. It could also help to address contextual modulation of active sensing during touch-induced whisking in head-fixed vs freely behaving animals. Finally, it provides the necessary data for machine learning approaches for automated analysis of sensory and motion parameters across a wide variety of signal-to-noise ratios with accompanying human observer-determined ground-truth.
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Affiliation(s)
- Alireza Azarfar
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands
| | - Yiping Zhang
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands
| | - Artoghrul Alishbayli
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands
| | - Stéphanie Miceli
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical School, Kapittelweg 29, Nijmegen, 6525 EN The Netherlands
| | - Lara Kepser
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical School, Kapittelweg 29, Nijmegen, 6525 EN The Netherlands
| | - Daan van der Wielen
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands
| | - Mike van de Moosdijk
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands
| | - Judith Homberg
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical School, Kapittelweg 29, Nijmegen, 6525 EN The Netherlands
| | - Dirk Schubert
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands.,Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical School, Kapittelweg 29, Nijmegen, 6525 EN The Netherlands
| | - Rémi Proville
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands
| | - Tansu Celikel
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 HJ The Netherlands
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28
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Chaudhary R, Rema V. Deficits in Behavioral Functions of Intact Barrel Cortex Following Lesions of Homotopic Contralateral Cortex. Front Syst Neurosci 2018; 12:57. [PMID: 30524251 PMCID: PMC6262316 DOI: 10.3389/fnsys.2018.00057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/17/2018] [Indexed: 12/02/2022] Open
Abstract
Focal unilateral injuries to the somatosensory whisker barrel cortex have been shown cause long-lasting deficits in the activity and experience-dependent plasticity of neurons in the intact contralateral barrel cortex. However, the long-term effect of these deficits on behavioral functions of the intact contralesional cortex is not clear. In this study, we used the “Gap-crossing task” a barrel cortex-dependent, whisker-sensitive, tactile behavior to test the hypothesis that unilateral lesions of the somatosensory cortex would affect behavioral functions of the intact somatosensory cortex and degrade the execution of a bilaterally learnt behavior. Adult rats were trained to perform the Gap-crossing task using whiskers on both sides of the face. The barrel cortex was then lesioned unilaterally by subpial aspiration. As observed in other studies, when rats used whiskers that directly projected to the lesioned hemisphere the performance of Gap-crossing was drastically compromised, perhaps due to direct effect of lesion. Significant and persistent deficits were present when the lesioned rats performed Gap-crossing task using whiskers that projected to the intact cortex. The deficits were specific to performance of the task at the highest levels of sensitivity. Comparable deficits were seen when normal, bilaterally trained, rats performed the Gap-crossing task with only the whiskers on one side of the face or when they used only two rows of whiskers (D row and E row) intact on both side of the face. These findings indicate that the prolonged impairment in execution of the learnt task by rats with unilateral lesions of somatosensory cortex could be because sensory inputs from one set of whiskers to the intact cortex is insufficient to provide adequate sensory information at higher thresholds of detection. Our data suggest that optimal performance of somatosensory behavior requires dynamic activity-driven interhemispheric interactions from the entire somatosensory inputs between homotopic areas of the cerebral cortex. These results imply that focal unilateral cortical injuries, including those in humans, are likely to have widespread bilateral effects on information processing including in intact areas of the cortex.
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Affiliation(s)
| | - V Rema
- National Brain Research Centre, Manesar, India
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29
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Kole K, Celikel T. Neocortical Microdissection at Columnar and Laminar Resolution for Molecular Interrogation. ACTA ACUST UNITED AC 2018; 86:e55. [PMID: 30285322 DOI: 10.1002/cpns.55] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The heterogeneous organization of the mammalian neocortex poses a challenge for elucidating the molecular mechanisms underlying its physiological processes. Although high-throughput molecular methods are increasingly deployed in neuroscience, their anatomical specificity is often lacking. In this unit, we introduce a targeted microdissection technique that enables extraction of high-quality RNA and proteins at high anatomical resolution from acutely prepared brain slices. We exemplify its utility by isolating single cortical columns and laminae from the mouse primary somatosensory (barrel) cortex. Tissues can be isolated from living slices in minutes, and the extracted RNA and protein are of sufficient quantity and quality to be used for RNA sequencing and mass spectrometry. This technique will help to increase the anatomical specificity of molecular studies of the neocortex, and the brain in general, as it is applicable to any brain structure that can be identified using optical landmarks in living slices. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Koen Kole
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Tansu Celikel
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands
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30
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Goel A, Cantu DA, Guilfoyle J, Chaudhari GR, Newadkar A, Todisco B, de Alba D, Kourdougli N, Schmitt LM, Pedapati E, Erickson CA, Portera-Cailliau C. Impaired perceptual learning in a mouse model of Fragile X syndrome is mediated by parvalbumin neuron dysfunction and is reversible. Nat Neurosci 2018; 21:1404-1411. [PMID: 30250263 PMCID: PMC6161491 DOI: 10.1038/s41593-018-0231-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 08/06/2018] [Indexed: 12/26/2022]
Abstract
To uncover the circuit-level alterations that underlie atypical sensory processing associated with autism, we adopted a symptom-to-circuit approach in the Fmr1-knockout (Fmr1-/-) mouse model of Fragile X syndrome. Using a go/no-go task and in vivo two-photon calcium imaging, we find that impaired visual discrimination in Fmr1-/- mice correlates with marked deficits in orientation tuning of principal neurons and with a decrease in the activity of parvalbumin interneurons in primary visual cortex. Restoring visually evoked activity in parvalbumin cells in Fmr1-/- mice with a chemogenetic strategy using designer receptors exclusively activated by designer drugs was sufficient to rescue their behavioral performance. Strikingly, human subjects with Fragile X syndrome exhibit impairments in visual discrimination similar to those in Fmr1-/- mice. These results suggest that manipulating inhibition may help sensory processing in Fragile X syndrome.
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Affiliation(s)
- Anubhuti Goel
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Daniel A Cantu
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Janna Guilfoyle
- Department of Psychiatry, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Gunvant R Chaudhari
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Aditi Newadkar
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Barbara Todisco
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Diego de Alba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Nazim Kourdougli
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Lauren M Schmitt
- Department of Psychiatry, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Ernest Pedapati
- Department of Psychiatry, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Department of Neurology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Craig A Erickson
- Department of Psychiatry, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Carlos Portera-Cailliau
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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31
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Azarfar A, Calcini N, Huang C, Zeldenrust F, Celikel T. Neural coding: A single neuron's perspective. Neurosci Biobehav Rev 2018; 94:238-247. [PMID: 30227142 DOI: 10.1016/j.neubiorev.2018.09.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 08/27/2018] [Accepted: 09/07/2018] [Indexed: 12/15/2022]
Abstract
What any sensory neuron knows about the world is one of the cardinal questions in Neuroscience. Information from the sensory periphery travels across synaptically coupled neurons as each neuron encodes information by varying the rate and timing of its action potentials (spikes). Spatiotemporally correlated changes in this spiking regimen across neuronal populations are the neural basis of sensory representations. In the somatosensory cortex, however, spiking of individual (or pairs of) cortical neurons is only minimally informative about the world. Recent studies showed that one solution neurons implement to counteract this information loss is adapting their rate of information transfer to the ongoing synaptic activity by changing the membrane potential at which spike is generated. Here we first introduce the principles of information flow from the sensory periphery to the primary sensory cortex in a model sensory (whisker) system, and subsequently discuss how the adaptive spike threshold gates the intracellular information transfer from the somatic post-synaptic potential to action potentials, controlling the information content of communication across somatosensory cortical neurons.
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Affiliation(s)
- Alireza Azarfar
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour Radboud University, the Netherlands
| | - Niccoló Calcini
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour Radboud University, the Netherlands
| | - Chao Huang
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour Radboud University, the Netherlands
| | - Fleur Zeldenrust
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour Radboud University, the Netherlands
| | - Tansu Celikel
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour Radboud University, the Netherlands.
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32
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Kole K, Scheenen W, Tiesinga P, Celikel T. Cellular diversity of the somatosensory cortical map plasticity. Neurosci Biobehav Rev 2017; 84:100-115. [PMID: 29183683 DOI: 10.1016/j.neubiorev.2017.11.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 11/21/2017] [Accepted: 11/21/2017] [Indexed: 01/23/2023]
Abstract
Sensory maps are representations of the sensory epithelia in the brain. Despite the intuitive explanatory power behind sensory maps as being neuronal precursors to sensory perception, and sensory cortical plasticity as a neural correlate of perceptual learning, molecular mechanisms that regulate map plasticity are not well understood. Here we perform a meta-analysis of transcriptional and translational changes during altered whisker use to nominate the major molecular correlates of experience-dependent map plasticity in the barrel cortex. We argue that brain plasticity is a systems level response, involving all cell classes, from neuron and glia to non-neuronal cells including endothelia. Using molecular pathway analysis, we further propose a gene regulatory network that could couple activity dependent changes in neurons to adaptive changes in neurovasculature, and finally we show that transcriptional regulations observed in major brain disorders target genes that are modulated by altered sensory experience. Thus, understanding the molecular mechanisms of experience-dependent plasticity of sensory maps might help to unravel the cellular events that shape brain plasticity in health and disease.
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Affiliation(s)
- Koen Kole
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands; Department of Neuroinformatics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands.
| | - Wim Scheenen
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Paul Tiesinga
- Department of Neuroinformatics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Tansu Celikel
- Department of Neurophysiology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands
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33
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The non-coding RNA BC1 regulates experience-dependent structural plasticity and learning. Nat Commun 2017; 8:293. [PMID: 28819097 PMCID: PMC5561022 DOI: 10.1038/s41467-017-00311-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 06/19/2017] [Indexed: 11/09/2022] Open
Abstract
The brain cytoplasmic (BC1) RNA is a non-coding RNA (ncRNA) involved in neuronal translational control. Absence of BC1 is associated with altered glutamatergic transmission and maladaptive behavior. Here, we show that pyramidal neurons in the barrel cortex of BC1 knock out (KO) mice display larger excitatory postsynaptic currents and increased spontaneous activity in vivo. Furthermore, BC1 KO mice have enlarged spine heads and postsynaptic densities and increased synaptic levels of glutamate receptors and PSD-95. Of note, BC1 KO mice show aberrant structural plasticity in response to whisker deprivation, impaired texture novel object recognition and altered social behavior. Thus, our study highlights a role for BC1 RNA in experience-dependent plasticity and learning in the mammalian adult neocortex, and provides insight into the function of brain ncRNAs regulating synaptic transmission, plasticity and behavior, with potential relevance in the context of intellectual disabilities and psychiatric disorders. Brain cytoplasmic (BC1) RNA is a non-coding RNA that has been implicated in translational regulation, seizure, and anxiety. Here, the authors show that in the cortex, BC1 RNA is required for sensory deprivation-induced structural plasticity of dendritic spines, as well as for correct sensory learning and social behaviors.
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34
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Enhanced Excitatory Connectivity and Disturbed Sound Processing in the Auditory Brainstem of Fragile X Mice. J Neurosci 2017; 37:7403-7419. [PMID: 28674175 DOI: 10.1523/jneurosci.2310-16.2017] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 06/06/2017] [Accepted: 06/15/2017] [Indexed: 12/11/2022] Open
Abstract
Hypersensitivity to sounds is one of the prevalent symptoms in individuals with Fragile X syndrome (FXS). It manifests behaviorally early during development and is often used as a landmark for treatment efficacy. However, the physiological mechanisms and circuit-level alterations underlying this aberrant behavior remain poorly understood. Using the mouse model of FXS (Fmr1 KO), we demonstrate that functional maturation of auditory brainstem synapses is impaired in FXS. Fmr1 KO mice showed a greatly enhanced excitatory synaptic input strength in neurons of the lateral superior olive (LSO), a prominent auditory brainstem nucleus, which integrates ipsilateral excitation and contralateral inhibition to compute interaural level differences. Conversely, the glycinergic, inhibitory input properties remained unaffected. The enhanced excitation was the result of an increased number of cochlear nucleus fibers converging onto one LSO neuron, without changing individual synapse properties. Concomitantly, immunolabeling of excitatory ending markers revealed an increase in the immunolabeled area, supporting abnormally elevated excitatory input numbers. Intrinsic firing properties were only slightly enhanced. In line with the disturbed development of LSO circuitry, auditory processing was also affected in adult Fmr1 KO mice as shown with single-unit recordings of LSO neurons. These processing deficits manifested as an increase in firing rate, a broadening of the frequency response area, and a shift in the interaural level difference function of LSO neurons. Our results suggest that this aberrant synaptic development of auditory brainstem circuits might be a major underlying cause of the auditory processing deficits in FXS.SIGNIFICANCE STATEMENT Fragile X Syndrome (FXS) is the most common inheritable form of intellectual impairment, including autism. A core symptom of FXS is extreme sensitivity to loud sounds. This is one reason why individuals with FXS tend to avoid social interactions, contributing to their isolation. Here, a mouse model of FXS was used to investigate the auditory brainstem where basic sound information is first processed. Loss of the Fragile X mental retardation protein leads to excessive excitatory compared with inhibitory inputs in neurons extracting information about sound levels. Functionally, this elevated excitation results in increased firing rates, and abnormal coding of frequency and binaural sound localization cues. Imbalanced early-stage sound level processing could partially explain the auditory processing deficits in FXS.
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35
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Tactile Defensiveness and Impaired Adaptation of Neuronal Activity in the Fmr1 Knock-Out Mouse Model of Autism. J Neurosci 2017; 37:6475-6487. [PMID: 28607173 DOI: 10.1523/jneurosci.0651-17.2017] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 05/17/2017] [Accepted: 05/24/2017] [Indexed: 11/21/2022] Open
Abstract
Sensory hypersensitivity is a common symptom in autism spectrum disorders (ASDs), including fragile X syndrome (FXS), and frequently leads to tactile defensiveness. In mouse models of ASDs, there is mounting evidence of neuronal and circuit hyperexcitability in several brain regions, which could contribute to sensory hypersensitivity. However, it is not yet known whether or how sensory stimulation might trigger abnormal sensory processing at the circuit level or abnormal behavioral responses in ASD mouse models, especially during an early developmental time when experience-dependent plasticity shapes such circuits. Using a novel assay, we discovered exaggerated motor responses to whisker stimulation in young Fmr1 knock-out (KO) mice (postnatal days 14-16), a model of FXS. Adult Fmr1 KO mice actively avoided a stimulus that was innocuous to wild-type controls, a sign of tactile defensiveness. Using in vivo two-photon calcium imaging of layer 2/3 barrel cortex neurons expressing GCaMP6s, we found no differences between wild-type and Fmr1 KO mice in overall whisker-evoked activity, though 45% fewer neurons in young Fmr1 KO mice responded in a time-locked manner. Notably, we identified a pronounced deficit in neuronal adaptation to repetitive whisker stimulation in both young and adult Fmr1 KO mice. Thus, impaired adaptation in cortical sensory circuits is a potential cause of tactile defensiveness in autism.SIGNIFICANCE STATEMENT We use a novel paradigm of repetitive whisker stimulation and in vivo calcium imaging to assess tactile defensiveness and barrel cortex activity in young and adult Fmr1 knock-out mice, the mouse model of fragile X syndrome (FXS). We describe evidence of tactile defensiveness, as well as a lack of L2/3 neuronal adaptation in barrel cortex, during whisker stimulation. We propose that a defect in sensory adaptation within local neuronal networks, beginning at a young age and continuing into adulthood, likely contributes to sensory overreactivity in FXS and perhaps other ASDs.
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36
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Miceli S, Nadif Kasri N, Joosten J, Huang C, Kepser L, Proville R, Selten MM, van Eijs F, Azarfar A, Homberg JR, Celikel T, Schubert D. Reduced Inhibition within Layer IV of Sert Knockout Rat Barrel Cortex is Associated with Faster Sensory Integration. Cereb Cortex 2017; 27:933-949. [PMID: 28158484 PMCID: PMC5390402 DOI: 10.1093/cercor/bhx016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 12/07/2016] [Accepted: 01/11/2017] [Indexed: 12/19/2022] Open
Abstract
Neural activity is essential for the maturation of sensory systems. In the rodent primary somatosensory cortex (S1), high extracellular serotonin (5-HT) levels during development impair neural transmission between the thalamus and cortical input layer IV (LIV). Rodent models of impaired 5-HT transporter (SERT) function show disruption in their topological organization of S1 and in the expression of activity-regulated genes essential for inhibitory cortical network formation. It remains unclear how such alterations affect the sensory information processing within cortical LIV. Using serotonin transporter knockout (Sert-/-) rats, we demonstrate that high extracellular serotonin levels are associated with impaired feedforward inhibition (FFI), fewer perisomatic inhibitory synapses, a depolarized GABA reversal potential and reduced expression of KCC2 transporters in juvenile animals. At the neural population level, reduced FFI increases the excitatory drive originating from LIV, facilitating evoked representations in the supragranular layers II/III. The behavioral consequence of these changes in network excitability is faster integration of the sensory information during whisker-based tactile navigation, as Sert-/- rats require fewer whisker contacts with tactile targets and perform object localization with faster reaction times. These results highlight the association of serotonergic homeostasis with formation and excitability of sensory cortical networks, and consequently with sensory perception.
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Affiliation(s)
- Stéphanie Miceli
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Department of Neural Networks, Center of Advanced European Studies and Research (caesar), Max Planck Society, Germany
| | - Nael Nadif Kasri
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Joep Joosten
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Chao Huang
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Lara Kepser
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Rémi Proville
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Martijn M. Selten
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Fenneke van Eijs
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Alireza Azarfar
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Judith R. Homberg
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Tansu Celikel
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Department of Neurophysiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
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